Objectives: It is desirable that the surfaces of surgical implants be
uncontaminated by foreign materials to avoid untoward tissue reactions
, and grit blasting is widely assumed to leave clean metal surfaces. S
EM examination and X-ray microanalysis of a recovered 'pure' titanium
implant casting that was associated with tissue breakdown revealed emb
edded particles of alumina. The casting had been cleaned of investment
by blasting with alumina grit. Methods: A variety of treatments of ca
st titanium plates was used: (a) to establish that the observed alumin
ium was due to the blasting grit, and (b) to determine whether removal
of investment could be achieved effectively by other means. SEM exami
nation and X-ray microanalysis were used. Results: The detected alumin
ium was associated with embedded fragments identified as coming from t
he blasting grit. Acid-pickling and mechanical (rotary instrument) tri
mming produced minimally contaminated surfaces. Conclusions: Whilst un
proven, the presence of the alumina is viewed with great concern as a
possible causative agent in the observed tissue breakdown and procedur
es avoiding alumina blasting are recommended as a precautionary measur
e.